ROUTE(1M)ROUTE(1M)NAMEroute - manually manipulate the routing tables
SYNOPSISroute [-fnvq] sub-command [ [modifiers] args]
route [-fnvq] [-p [-R root-dir]] add | delete [modifiers] destination gateway
[args]
route [-fnvq] change | get [modifiers] destination
[gateway [args]]
route [-fn] monitor [modifiers]
route [-fnvq] flush [modifiers]
route-p [-R root-dir] show
DESCRIPTIONroute manually manipulates the network routing tables. These tables are
normally maintained by the system routing daemon, such as in.routed(1M)
and in.ripngd(1M).
route supports a limited number of general options, but a rich command
language. Users can specify an arbitrary request that can be delivered
by means of the programmatic interface discussed in route(7P).
route uses a routing socket and the new message types RTM_ADD,
RTM_DELETE, RTM_GET, and RTM_CHANGE. While only superusers can modify
routing tables, the RTM_GET operation is allowed for non-privileged
users.
OPTIONS-f
Flush the routing tables of all gateway entries. If you
use the -f option in conjunction with any of the route
sub-commands, route flushes the gateways before perform‐
ing the sub-command. Specify the table to flush by plac‐
ing the inet or inet6 modifier immediately after the -f
option. If unspecified, flushing IPv4 (inet) routes is
the default.
-n
Prevent attempts to print host and network names symbol‐
ically when reporting actions. This option is useful
when name servers are unavailable.
-p
Make changes to the network route tables persistent
across system restarts. The operation is applied to the
network routing tables first and, if successful, is then
applied to the list of saved routes used at system
startup. In determining whether an operation was suc‐
cessful, a failure to add a route that already exists or
to delete a route that is not in the routing table is
ignored. Particular care should be taken when using
host or network names in persistent routes, as network-
based name resolution services are not available at the
time routes are added at startup.
-q
Suppress all output.
-R root-dir
Specify an alternate root directory where route applies
changes. This option is ignored unless used in conjunc‐
tion with the -p option. When -R is specified, route
changes are applied only to the list of saved routes to
be used at startup, not to the network routing tables.
In addition, certain checks, such as the existence of
network interfaces used with -ifp, are skipped. This can
be useful from within JumpStart scripts, where the root
directory of the system being modified is in a location
other than /.
-v
Print additional details in verbose mode.
Subcommands
The following subcommands are supported:
add
Add a route.
change
Change aspects of a route (such as its gateway).
delete
Delete a specific route.
flush
Remove all gateway entries from the routing table.
get
Look up and display the route for a destination.
monitor
Continuously report any changes to the routing information
base, routing lookup misses, or suspected network partition‐
ings.
show
Display the list of routes to be applied at system startup.
Can be used only in conjunction with the -p option.
The add and delete sub-commands have the following syntax:
route [ -fnvq ] cmd destination gateway [metric/netmask]
where cmd is add or delete, destination is the destination host or net‐
work, and gateway is the next-hop intermediary through which packets
should be routed. Modifiers described in OPERANDS can be placed any‐
where on the command line.
The get and change sub-commands have the following syntax:
route [ -fnvq ] cmd destination [gateway [metric/netmask]]
where cmd is get or change, destination is the destination host or net‐
work, and gateway is the next-hop intermediary through which packets
should be routed. Modifiers described in OPERANDS can be placed any‐
where on the command line.
The monitor sub-command has the following syntax:
route monitor [ -inet | -inet6 ]
OPERANDSroute executes its sub-commands on routes to destinations by way of
gateways.
Destinations and Gateways
By default, destination and gateway addresses are interpreted as IPv4
addresses. All symbolic names are tried first as a host name, using
getipnodebyname(3SOCKET). If this lookup fails in the AF_INET case,
getnetbyname(3SOCKET) interprets the name as that of a network.
Including an optional modifier on the command line before the address
changes how the route sub-command interprets it.
The following modifiers are supported:
-inet
Force the address to be interpreted as an IPv4 address, that
is, under the AF_INET address family.
-inet6
Force the address to be interpreted as an IPv6 address, that
is, under the AF_INET6 address family.
For IPv4 addresses, routes to a particular host are by default distin‐
guished from those to a network by interpreting the Internet address
specified as the destination. If the destination has a local address
part (that is, the portion not covered by the netmask) of 0, or if the
destination is resolved as the symbolic name of a network, then the
route is assumed to be to a network; otherwise, it is presumed to be a
route to a host.
You can force this selection by using one of the following modifiers:
-host
Force the destination to be interpreted as a host.
-net
Force the destination to be interpreted as a network.
For example:
Destination Destination Equivalent
─────────────────────────────────────────
128.32 -host 128.0.0.32
128.32.130 -host 128.32.0.130
-net 128.32 128.32.0.0
-net 128.32.130 128.32.130.0
Two modifiers avoid confusion between addresses and keywords (for exam‐
ple., host used as a symbolic host name). You can distinguish a desti‐
nation by preceding it with the -dst modifier. You can distinguish a
gateway address by using the -gateway modifier. If the destination is
directly reachable by way of an interface requiring no intermediary IP
router to act as a gateway, this can be indicated by using the -inter‐
face or -iface modifier.
In the following example, the route does not refer to an external gate‐
way (router), but rather to one of the machine's interfaces. Packets
with IP destination addresses matching the destination and mask on such
a route are sent out on the interface identified by the gateway
address. For interfaces using the ARP protocol, this type of route is
used to specify that all matching destinations are local to the physi‐
cal link. That is, a host could be configured to ARP for all addresses,
without regard to the configured interface netmask, by adding a default
route using this command. For example:
example# route add default hostname -interface
where gateway address hostname is the name or IP address associated
with the network interface over which all matching packets should be
sent. On a host with a single network interface, hostname is usually
the same as the nodename returned by the uname -n command. See
uname(1).
For backward compatibility with older systems, directly reachable
routes can also be specified by placing a 0 after the gateway address:
example# route add default hostname 0
This value was once a route metric, but this metric is no longer used.
If the value is specified as 0, then the destination is directly reach‐
able (equivalent to specifying -interface). If it is non-zero but can‐
not be interpreted as a subnet mask, then a gateway is used (default).
With the AF_INET address family or an IPv4 address, a separate subnet
mask can be specified. This can be specified in one of the following
ways:
o IP address following the gateway address . This is typically
specified in decimal dot notation as for inet_addr(3SOCKET)
rather than in symbolic form.
o IP address following the -netmask qualifier.
o Slash character and a decimal length appended to the desti‐
nation address.
If a subnet mask is not specified, the mask used is the subnet mask of
the output interface selected by the gateway address, if the classful
network of the destination is the same as the classful network of the
interface. Otherwise, the classful network mask for the destination
address is used.
Each of the following examples creates an IPv4 route to the destination
192.0.2.32 subnet with a subnet mask of 255.255.255.224:
example# route add 192.0.2.32/27 somegateway
example# route add 192.0.2.32 -netmask 255.255.255.224 somegateway
example# route add 192.0.2.32 somegateway 255.255.255.224
For IPv6, only the slash format is accepted. The following example cre‐
ates an IPv6 route to the destination 33fe:: with a netmask of 16 one-
bits followed by 112 zero-bits.
example# route add -inet6 3ffe::/16 somegateway
In cases where the gateway does not uniquely identify the output inter‐
face (for example, when several interfaces have the same address), you
can use the -ifp ifname modifier to specify the interface by name. For
example, -ifp lo0 associates the route with the lo0 interface. If the
named interface is an underlying interface in an IPMP (IP multipathing)
group, then requests to add a route will automatically be translated to
the corresponding IPMP IP interface, and requests to delete or change a
route on an underlying interface will fail.
Routing Flags
Routes have associated flags that influence operation of the protocols
when sending to destinations matched by the routes. These flags can be
set (and in some cases cleared, indicated by ~) by including the fol‐
lowing modifiers on the command line:
Modifier Flag Description
────────────────────────────────────────────────────────────────────
-interface ~RTF_GATEWAY Destination is directly reachable
-iface ~RTF_GATEWAY Alias for interface modifier
-static RTF_STATIC Manually added route-nostatic ~RTF_STATIC Pretend route was added by kernel or
routing daemon
-reject RTF_REJECT Emit an ICMP unreachable when matched
-blackhole RTF_BLACKHOLE Silently discard packets duing updates
-proto1 RTF_PROTO1 Set protocol specific routing flag #1
-proto2 RTF_PROTO2 Set protocol specific routing flag #2
-private RTF_PRIVATE Do not advertise this route-multirt RTF_MULTIRT Creates the specified redundant route-setsrc RTF_SETSRC Assigns the default source address
The optional modifiers -rtt, -rttvar, -sendpipe, -recvpipe, -mtu, -hop‐
count, -expire, and -ssthresh provide initial values to quantities
maintained in the routing entry by transport level protocols, such as
TCP. These can be individually locked either by preceding each modifier
to be locked by the -lock meta-modifier, or by specifying that all
ensuing metrics can be locked by the -lockrest meta-modifier.
Some transport layer protocols can support only some of these metrics.
The following optional modifiers are supported:
-expire
Lifetime for the entry. This optional modifier is not cur‐
rently supported.
-hopcount
Maximum hop count. This optional modifier is not currently
supported.
-mtu
Maximum MTU in bytes.
-recvpipe
Receive pipe size in bytes.
-rtt
Round trip time in microseconds.
-rttvar
Round trip time variance in microseconds.
-sendpipe
Send pipe size in bytes.
-ssthresh
Send pipe size threshold in bytes.
-secattr
Security attributes of the route. This modifier is avail‐
able only if the system is configured with the Solaris
Trusted Extensions feature.
The -secattr modifier has the following format:
min_sl=val,max_sl=val,doi=val,cipso
or:
sl=VAL,doi=VAL,cipso
In the first form, above, the val for min_sl and max_sl is
a sensitivity label in either hex or string form. The val
for doi is a non-negative integer. The route will apply
only for packets with the same domain of interpretation as
defined by the doi value and within the accreditation
range defined by the min_sl and max_sl values. The cipso
keyword is optional and set by default. Valid min_sl,
max_sl and doi keyword/value pairs are mandatory. Note
that if val contains a space, it must be protected by dou‐
ble quotes.
The second form, above, is equivalent to specifying the
first form with the same VAL for min_sl and max_sl. The
second form should be used for the get command, because
get uses only a single sensitivity label.
Compatibility
The modifiers host and net are taken to be equivalent to -host and
-net. To specify a symbolic address that matches one of these names,
use the dst or gateway keyword to distinguish it. For example: -dst
host
The following two flags are also accepted for compatibility with older
systems, but have no effect.
Modifier Flag
─────────────────────────
-cloning RTF_CLONING
-xresolve RTF_XRESOLVE
The -ifa hostname modifier is also accepted, but has no effect.
FILES
/etc/defaultrouter
List of default routers
/etc/hosts
List of host names and net addresses
/etc/networks
List of network names and addresses
SEE ALSOuname(1), in.ripngd(1M), in.routed(1M), netstat(1M), routed(1M),
ioctl(2), getipnodebyname(3SOCKET), getnetbyname(3SOCKET),
inet_addr(3SOCKET), defaultrouter(4), hosts(4), networks(4),
attributes(5), ARP(7P), ip(7P), route(7P), routing(7P)DIAGNOSTICS
add [ host| network] destination:gateway flags
The specified route is being added to the tables. The values
printed are from the routing table entry supplied in the ioctl(2)
call. If the gateway address used was not the primary address of
the gateway (the first one returned by getipnodebyname(3SOCKET))
the gateway address is printed numerically as well as symbolically.
delete [ host| network] destination:gateway flags
change [ host| network] destination:gateway flags
As add, but when deleting or changing an entry.
destination done
When the -f flag is specified, or the flush sub-command is used,
each routing table entry deleted is indicated with a message of
this form.
Network is unreachable
An attempt to add a route failed because the gateway listed was not
on a directly-connected network. Give the next-hop gateway instead.
not in table
A delete operation was attempted for an entry that is not in the
table.
entry exists
An add operation was attempted for a route that already exists in
the kernel.
routing table overflow
An operation was attempted, but the system was unable to allocate
memory to create the new entry.
insufficient privileges
An attempt to add, delete, change, or flush a route failed because
the calling process does not have appropriate privileges.
NOTES
Specifying that destinations are local (with the -interfacemodifier)
assumes that the routers implement proxy ARP, meaning that they respond
to ARP queries for all reachable destinations. Normally, using either
router discovery or RIP is more reliable and scalable than using proxy
ARP. See in.routed(1M) for information related to RIP.
Combining the all destinations are local route with subnet or network
routes can lead to unpredictable results. The search order as it
relates to the all destinations are local route are undefined and can
vary from release to release.
Feb 3, 2009 ROUTE(1M)
